Cushion joint for rotary drill pipes



' n 1 192 Ma @h 7 A. c. HOPKINS CUSHION JOINT FOR ROTAY DRILL APPES Filed Feb. 4, 1924 u t. .Il

Patented Mar. 1, 1927.

UNITED STATES PATENT oFI-ICE ARTHUR C. HOPKINS, OF COMPTON, CALIFORNIA,

ASSIGNOR T0 U'. S. TOOL CO., A COR PORATION OF CALIFORNIA.

CUSHION JOINT FOR'ROTARY DRILL-runs.

Application med February 4, 1924. v:serial No. 690,507.

This invention relates to rotary drill pipes, and more particularly it relates to cushion joints for such pipes.

In drilling deep wells, such, for example, those having a depth of the order of 3000 feet, a metallic casing, comprising tubes secured end to end, is prov1ded to prevent the caving in of the strata bordering the well. In hydraulic rotary drilling of such wells, a string of connected metallic drill pipes rotates within the casing. When the string becomes very long, it is so flexible that its rotary motion causes itto whip aga-inst the casing and wear holes through it where the couplings and tool joints contact with it. Y

It is therefore an object of my invention to provi-de cushions, which are preferably made of rubber, on the drill pipes at suit- 'able intervalsand at suitable -positions to practically eliminate the wear on the casing.

In -employing cushions I prefer to position them at the pipe joints and in order to accomplish this successfully I use a novel' form of joint.

It is therefore another object of my invention to provide a special form of pipe connection and construction which may be used in combination with a cushion.

With the foregoing objects in View, together with such other objects and advantages as may subsequently appear, my invention consists in the construction and arrangement of partsV hereinafter described and claimed and illustrated in the accompanying drawings, in which l Figure lis a central longitudinal section through a section of drill pipe showing a cushion-retaining member interposed between the standard coupling and a'length' of drill pipe. "g. 1A. is a viewshowing the vparts in 1 disassembled.

to Fig. 1, show- 1ng a cushion-retaining member interposed between the pin and the box of a standard tool joint. .Y

Fig. 2A is a view of the parts shown in Fig. 2 disassembled.

Fig. 3 is a central longitudinal section of a well casing enclosing a string `of pipe y sections, twoA ofwhich are connectedv the device illustrated in Fi 1 Figi 4 is a central longitudinal section of a we body portion casing enclosing a string of pipes,

two of which are connected by the device illustrated in Fig. 2.

Fig. 5 isa central longitudinal section of a well casing and a string of pipes therein held together by the devices'illustrated in Figs. 1 and 2.

Referring'to Fig. l1 for a more detailed description of one form of my invention, the ,numeral 10 cindicates part ofa rota'ry drill pipe llength or section, the lower end of which is provided -with male threads 11 adapted'to engage a' threaded recess formed in the upper' end of a tubular member 12. The member 12 is reduced in diameter in its lower portion, forming a shoulder or oli'- set- 13 and is threaded at its lower end portion 14 which engages the upper part of a standard coupling 15, the lower part of which engages a threaded upper end poredge of 'the 'cushi'on'abutting a ainst the shoulder 13 and the lower edge o the cushv ion abutting against the upper edge of the couplinvr 15. I

In Ilig. 2, a cushion-retaining tubular member 20 is interposed between a pin P and a box B of a standard tool joint.

The cushion-retaining member is comparatively short, usually about 18 to 20 inches long, and comprises a body portion 21 having a head 22 provided with a female thread 23 adapted to receive the male thread of the tool jointr'pin P, the head portion being of the same diameter as that of the of the pin while a reduced portion 24 is 25 and terminates with a male thread 26.

.In\ order to hold the cushion on the portion 21 and lconnect with .the box of the tool joint, another tubular member 27 is provided having avfemale threaded portion 28 at one end adapted' to `engage the male thread 26 while the other end is provided with a male thread 29 adapted to engage the thread of the tool` joint box B.

It will 'be understood that after the cush ion has been placed onthe portion 21 of the member 20,v the members 20 and 27 are 'then screwed tightly together and thus form a unit that will not separate whenthe sections of pipe together with the pin and boxjare being disassembled.

ile unscrewLing the -sections of drill utilized to receive a cushion ico ' and pin or couplings but small enough -to allow the insertion of an over shot or fishing tool.

From the construction,'it will be seen that the cushions of my invention effectively prevent the coupling and tool joints ofthe vdrill pipe from Wearing openings in the casing and may be used in connection with the standard couplings or tool joints without making any alteration in same.

In Fig. 3, the usual tool joint is shown at 30, While at 31 the form of connection', with cushion, shown in Fig. l is-illustrated.

In Fig. 4,-the form of connection shown in Fig. 2 is illustrated as being used at 32, While at 33 the usual form of connection employing a coupling is illustrated.

In Fig. 5, 34 and 35 illustrate respectively, the use of the form of connections shown 1n Figs. 2 and l. p

While I have herein discribed one form of my invention, modifications thereof may be devised without departing from the spirit thereof, and it is to be understood that such modifications come Within the scope of this invention.

W'hat is claimed is 1. A string of rotary drill pipe in a hydraulic rotary well drilling apparatus. c omprising a plurality of pipe sections, couplings uniting said sections at different points along the string, and resilient .cushions mounted on and held by said couplmgs.

v2. A string of rotary drill pipe in a hydraulic rotary Well drilling apparatus, comprising a plurality of pipe sections, couplings unitmg said sections, and resilient cushions mounted on rthe couplings and held by engagement with the members thereof.

3. In a rotary drill pipe, a cushion-retaining member having a threaded male end portion and a cushion encircling said member and partially embedded in the peri hery thereof, and a tubulanmember threa ed to the cushion-retaining member, .one end of said cushion being held against a shoulder formed in the cushion-retaining member, and the other end of said cushion abutting against the end of the tubular member.

4. In a rotary drill pipe, a cushion-retaining member having a threaded male end portion and a cushion encircling said member and partially embedded in the periphery thereof and a. coupling threaded to the male end portion of said member, one end of said cushion being held against a shoulder formed in the cushion-retaining member and the other end of said cushion abutting 'against an end of said coupling.

In a rotary drill pipe, a cushion-retaining member having an external shoulder formed thereon, a tubular member attach- `able to said cushion-retaining member and -positioned against said shoulder, and a second tubular section threaded -upon said section and tightened against said cushion for maintaining the cushion upon the first mentioned section against rotation`V thereon.

In testimony whereof I have signed my name to this specification.

ARTHUR C. HOPKINS. 

